a) Field of the Invention
The invention relates in general to a processing method for a lens film, and more particular to a processing method for attaching a film having optical properties onto a surface of a lens. A master slice has a surface formed with a microstructure during a cleaning process, and is pressed with a base plate having a curvature in a mold to form a lens with optical properties, thereby achieving advantages of attaching the master slice and the base plate with no bubbles in between, optimal wrinkle-free attaching effects and outstanding optical properties.
b) Description of the Prior Art
In current conventional eyeglass lenses, apart from basic configurations of plain mirrors, convex lenses and concave lenses. To append other optical effects, a film layer capable of producing expected optical effects may be additional attached or coated onto a lens. Such additional film layer may be a polarizing film, a color filter film or a lens protecting film. For example, a lens having a surface attached with a polarizing film becomes a polarizing lens. The function of the polarizing film is equivalent to blinds used for a window, and effectively blocks horizontal light rays while allowing only vertical light rays to pass through. As light rays can only move forward along the same direction, such light rays are referred to as polarized light rays. A polarizing lens mainly eliminates glare coming from all directions, and effectively increases the clarity of vision to reduce eye fatigue and dryness, thereby bringing better visual effects and quality. Thus, polarized lenses are extensively applied in are numerous structures including camera equipments and apparatus panels.
A manufacturing process of a conventional polycarbonate (PC) polarized lens is taken as an example. A shaping process is performed on a polarized film (to be referred to as a base plate), which is then cut. The cut base plate is placed in a mold of an injection molding machine, and a heated PC material in a molten state in injected and combined with the base plate. After cooling and removal from the mold, steps of cleaning, coloring and reinforcing are performed. An inspection step for the lens quality is then performed to complete the manufacturing process of the PC polarized light lens. PC polarized lenses are mass produced, and require several days of working hours. Further, drawbacks of polarizing color shifts, stress marks and impurities are likely caused at a joining surface of the base plate with the PC in the high-temperature mold of the injection molding machine. Further, uneven colors and water marks may also be generated in the coloring step. These defects can only be found at the final inspection step, leading to a lower yield rate of finished products. Thus, the manufacturing process of conventional PC polarized lenses is not only time-consuming but also has increased costs due to a low yield rate.
A manufacturing process of a resin polarized lens is taken as an example. A shaping process is performed on a polarizing film (to be referred to as a base plate). Steps of injecting and manufacturing a rubber ring, and grinding and cleaning a glass mold are performed. A mold closing step is performed on the base plate and the glass mold. After pouring, the mold is heated in a curing oven, and hardening and joining are then completed after a long reaction time. Next, a first inspection operation is performed, followed by performing steps of cleaning, coloring and reinforcing. A second inspection operation is then performed. Resin polarizing lenses are also mass produced, and require several days of working hours that are even longer than the manufacturing process of PC polarizing lenses. Further, the yield rate of resin polarizing lenses is not effectively increased in comparison. Thus, resin polarizing lenses also consume large production costs as expected. Therefore, there is a need for developers, researchers and manufactures of lenses with other additional optical effects to provide for a solution that effectively increases the yield rate of a manufacturing process of lenses with other additional optical effects, so as to achieve advantages of attaching the master slice and the base plate with no bubbles in between, optimal wrinkle-free attaching effects and outstanding optical properties.